In a power supply control device, a switching device turns a main switch on or off to control supply of power via the main switch. When a battery supplies power to the switching device, a fuse is disposed in a first current path of an output current output from the switching device. A diode is disposed in a second current path of the output current different from the first current path. If a current flowing through the fuse increases to or above a first threshold, the fuse blows. If a current flowing through the diode increases to or above a second threshold, the diode blows.

A circuit interrupter including a current sensor having a normal sensor output and an over current detection output, a solid state switch module structured to have a closed state to allow current to flow through the circuit interrupter and an open state to interrupt current flowing through the circuit interrupter, a gate driver structured to control the solid state switch module including a desaturation function output, wherein the gate driver is structured to cause the solid state switch module to interrupt current flowing through the circuit interrupter when the DESAT function output changes to the on state, and an electronic trip circuit structured to output a trip signal to the gate driver when the normal sensor output reaches a first threshold level or the overcurrent detection output changes to the on state.

One example includes a power generator protection system. The system includes a circuit breaker configured, when triggered, to provide an open circuit in a power line configured to conduct a current between a power grid point-of-interconnect (POI) and a power generator system. The system also includes a programmable controller configured to monitor the current and to generate a dynamic current threshold based on the current. The programmable controller can further be configured to compare the current with the dynamic current threshold and to trigger the circuit breaker based on a difference of the current relative to the dynamic current threshold to set an arc flash incident energy level of the power generator system at or below a predetermined safety level.

The invention relates to a novel approach for the protection of electrical circuits from ground faults and parallel and series arc faults in a fully solid-state circuit configuration. Solid-state circuits and methods of use are described that provide the key functions of low-voltage DC power supply, mains voltage and current sensing, fault detection processing and high voltage electronic switching.

The invention relates to a novel approach for the protection of electrical circuits from ground faults and parallel and series arc faults in a fully solid-state circuit configuration. Solid-state circuits and methods of use are described that provide the key functions of low-voltage DC power supply, mains voltage and current sensing, fault detection processing and high voltage electronic switching.

A method for analyzing power quality events in an electrical system includes processing electrical measurement data from or derived from energy-related signals captured by at least one of a plurality of metering devices in the electrical system to generate or update a plurality of dynamic tolerance curves. Each of the plurality of dynamic tolerance curves characterizes a response characteristic of the electrical system at a respective metering point of a plurality of metering points in the electrical system. Power quality data from the plurality of dynamic tolerance curves is selectively aggregated to analyze power quality events in the electrical system.

According to one aspect of embodiments, a driver circuit having an overcurrent protection function includes a control signal generating circuit that outputs a Pulse Width Modulation (PWM) control signal for controlling turning ON and OFF of the output transistor that supplies output current to a load; and a control circuit that generates a signal indicating an overcurrent state when a count value of an overcurrent detecting signal exceeds a predetermined number, which indicates that a value of an output current of the output transistor within the predetermined time interval exceeds a predetermined threshold value.

A control system and method for sectionalizing switches and pulse-testing interrupter/reclosers in a distribution grid feeder which enables fault location, isolation and service restoration without requiring an external communications infrastructure to pass information between the switches. The method includes switches entering an armed state when they experience a high fault current during an initial fault event. Then, when the interrupter/recloser runs its test pulse sequence, any armed switch counts all test pulses as fault pulses, while non-armed switches count the test pulses as load pulses. Switches open to isolate the fault based on threshold values of fault pulse count and load pulse count. When an initially active interrupter/recloser completes its test pulse sequence, another interrupter/recloser begins its sequence, and all switches reconfigure their threshold values based on the new interrupter/recloser. Interrupter/reclosers after the initial device use a fast close-open event if necessary to arm some switches for proper fault-count opening.

A method for preventing ground fault in a three-phase electric transmission line system caused by a line break, includes: providing a programmable relay protection system, including a plurality of relay devices on each line, programmed to include: preset parameter ranges of at least two electric operating conditions, at least one high sensitivity instantaneous undercurrent and at least one high sensitivity condition selected from line differential overcurrent and negative sequence overcurrent (and combinations thereof), the preset ranges being acceptable operating parameter ranges; monitoring; permitting closed circuit operation when all of the lines show that the two operating conditions are within the preset acceptable operating parameter ranges; tripping a circuit breaker on a broken line when that line shows that the two operating conditions are outside the preset parameter ranges; and shutting down power to the broken line before it otherwise causes a ground fault or other short circuit.

A system and method for nuisance-trip decision management in an electric power system using data analytics comprising, a protection system, PS, and at least one electrical protection circuit, EPC. The PS comprising, a plurality of sensors configured to measure data; a memory configured to store an updated data of nuisance-trip events and a plurality of nuisance-trip parameters detected or generated on the electric power system over a period; a processor configured to perform hybrid machine learning (HML) based on the measured data from the plurality of sensors for a nuisance-trip condition and communicate with a neighboring PS; a protection microcontroller configured to allow or avoid tripping at least one electronic tripping circuit provided in the at least one EPC by communicating with the processor and the neighboring PS.